Continuous monitoring of various physiological signals, such as blood pressure, tissue perfusion, and cardiac output, can provide important data for physicians when monitoring and treating various conditions. For example, keeping track of conditions such as elevated blood pressure is vital in the prevention and treatment of various blood-pressure-related diseases. However, continuous monitoring of some physiological signals with existing commonly used technology (e.g., cuff-based devices) can be difficult, uncomfortable, and impractical to perform in real-world settings (e.g., at work, while commuting, etc.).
Some current monitoring technologies are based on measuring a photoplethysmographic signal (PPG signal), and utilizing the PPG signal to calculate physiological signals, such as blood pressure. While such technologies may be more comfortable and portable than the cuff-based blood pressure monitors, they tend to be effected by the posture of the monitored person. For example, the posture may introduce artifacts that may unduly influence the shape of a cardiac waveform, which can lead to inaccurate calculations of physiological signals.
Thus, there is a need for systems that enable comfortable and practical monitoring of physiological signals, such as blood pressure, tissue perfusion, and cardiac output, in a manner that adjusts for various postures that may be assumed.